• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.15-26
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• 2004

The calibration for systematic error in LiDAR is crucial for the accuracy of airborne laser scanning. The main error is the misalignment of platforms between INS(Inertial Navigation System) and Laser scanner For planimetrical calibration of LiDAR, the building is good feature which has great changes in height and continuous flat area in the top. The planimetry error(pitch, roll) is corrected by adjustment of height which is calculated from comparing ground control points(GCP) of building to laser scanning data. We can know scale correction of laser range by the comparison of LiDAR data and GCP is arranged at the end of scan angle where maximize the height error. The area for scale calibration have to be large flat and have almost same elevation. At 1000m for average flying height, The Accuracy of laser scanning data using LiDAR is within 110cm in height and ${\pm}$50cm in planmetry so we can use laser scanning data for generating 3D terrain surface, expecically digital surface model(DSM) which is difficult to measure by aerial photogrammetry in forest, coast, urban area of high buildings

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.04a
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• pp.485-490
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• 2004

Recently, distribution transfer velocity was extremely lowered by high supply rate of vehicle and low road rate. Therefore expansions of transfer network these were subway, road and railway to recover competitive power as a reform measure of physical distribution traffic were become preference previous subject. For reason of that, an expansion of transfer network is meeting competitive power as selected an elevated road in the ground road network that condition of location calm and get out of the existing urban than the underground road to connect oversensitive a large city and expanded small and medium satellite town. In the meantime, while elevated structures construct, they go through the civilian residential section, agriculture land, etc. The consequence is that it raises a vibration, noise, dust, an infringement of the right to a view and an infringement of the right to a sunshine. In this study, we analyzed Quantitatively sunshine quantity with building 3D simulation model of civil structure. Therefore, we present as planning data to reduce a civilian appeal for dispute of the right to sunshine and an economic and time loss between the government and construction company In addition to that, for the standard of the standard plan of usable sunshine quantity program in the practical business, the building of convenient user interface will be the project to be done.

• KIEAE Journal
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• v.10 no.2
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• pp.63-69
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• 2010

Diverse problems in wind environment has occurred through rapid urbanization and growth of high-rise building numbers, This study aims to propose the CFD (Computational Fluid Dynamics) simulation method and evaluation standard of wind environment in site planning of high rise apartment housing. The CFD simulation method proposed in this study is not existing detail simulation, but it is the method that a designer can correct and develop the design through immediate evaluation of design options in concept design phase. Therefore, the proposed CFD simulation method of wind environment in this study uses the BIM based CFD tool in which the 3D model in concept design phase can be used as for the CFD simulation. In this paper, the study examines existing evaluation standards of comfortableness level in wind environment for pedestrian near buildings, and selects new evaluation method which is possible to apply to the proposed CFD simulation method. In addition, it is to examine calculation time-spending and appropriate mesh division method for finding CFD result which is useful to find the best design options in aspect of wind environment in concept design phase. Furthermore, it proposes the wind environment evaluation method through BIM based CFD simulation.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.285-287
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• 2010

It is recently enlarged to necessity of 3D spatial information model in urban areas. and in order to that, It is increased to use the terrestrial LiDAR. The Point clouds which are received by terrestrial LiDAR take a relateive coordinate. For transform into absolute coordinate, it carry out GPS surveying. However, it is difficult to geo-referencing of point clouds using the GPS due to high buildings and facilities in urban area. This study suggests a methodology, that is geo-referencing of point clouds which is received from terresstrial LiDAR in urban area and then verified accuracy of geo-referencing of point clouds. In order to geo-Referencing of point clouds which are received in Engineering building of Yonsei Univ., it was be setout through GPS surveying, and then obtained absolute coordinate of real building. Using this coordinate, It was operated geo-referencing of point clouds, verified accuracy between check point and geo-referenced point clouds. As a result, RMSE of check point shows that GPS surveying is 6.9~8.0cm.

• Journal of KIBIM
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• v.1 no.2
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• pp.24-29
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• 2011

BIM technology, based on 3D model of civil engineering structures, creates and manages information of the structures throughout four stages: Planning, design, construction, and maintenance. BIM is now used around the globe for improvement of the construction productivity. However, in order to expect the efficient engineering work, collaboration system between participants in a construction project is necessary. Therefore, in this paper BIM based CPLM (Construction project lifecycle management) system was designed and developed by analyzing the requirements of participants of a construction project. CPLM system offers an environment which enables the sharing and management of information according to the each stage of construction. CPLM is expected to aid cooperative decision-making during the overall construction process through the process innovation and the efficient data management.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.355-361
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• 2009

Onshore wind farms having several problems, difficult to secure a building site and incur the enmity of the people. Therefore, offshore wind farms are increasingly expected, because there are huge resource and large site in offshore. If huge wind turbines are constructed, the offshore wind power base is concerned about subsidence. In order to confirm the ground stability, estimation of subsidence is necessary. In this paper, the subsidence is predicted by continuity model when the gravity and the mono-pile base are constructed on soft ground. The FLAC 3D, three dimensional FDM program, was adopted to analysis subsidence. Input factors are yielded by geological information at the yeompo quay in ulsan and the results of laboratory experiments. It has been compared that the original ground with improved ground under the gravity base, and constructed mono-pile under the mono-pile base.

• Korean Institute of Interior Design Journal
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• no.34
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• pp.157-164
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• 2002

Online business these days prone to approach their costumers with improved module and various interface via Internet. This is more than just an act of providing enhancement, but a mean of finding out the customer's demand by enlarging their selection. This, however, is related to the bits per second of supplemental service network.For example, supplemental services that were not possible in the 56K modem era are now possible due to the information super highway network. To grope for new means of approaching, the best way will be by developing media that will collect customer's demands. Until now, customer's demands were evaluated by miniatures of apartment building, model houses or rendered images produced by 3D graphic softwares and pictures. Analyses were not available until evaluation were produced.Nowadays, utilizing the advanced Internet interface tools and various new media, customers are sought before the construction thus various studies to full fill the customer's demands are in process. This study is on development of a virtual module utilizing activated web environment. Analysis modules repeating the changes in customers are expected to deliver us a new trend.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.6
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• pp.55-66
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• 2011

The purpose of this study was to develop an efficient process in the design and construction of a 1:5 scale 10-story R.C. apartment building model for an earthquake simulation test. The reduction ratio of the specimen was determined by the size ($5m{\times}5m$) and pay load (600kN) of the available shaking table and the availability of model reinforcements. For efficiency and quality control of the reinforcement work, prefabrication was used. Construction was conducted in two steps, the wall in one step, and another step for the slab, because it was impossible to remove the formwork of a wall if the walls and slabs in a story were constructed in one step. The slip form construction method was used repetitively for walls. The formwork of a wall was made with veneer and acryl plate on each side, so it was possible to check the quality of the concrete placing. To construct this model, it took roughly six months with five full-time research assistants, for a total of 602 man days of labor in construction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.555-561
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• 2020

In this study, the applicability of Hunt's analytical solution for a two-layered leaky aquifer system, which was developed to estimate stream depletion due to the groundwater pumping of the upper shallow aquifer, was evaluated. The 5-year averaged stream depletions were estimated using Hunt's analytical solution for various combinations of hydraulic characteristic values such as transmissivity, storage coefficient of the two aquifers, interlayer leakage coefficient, stream-well distance, hydraulic conductivity of the streambed, and stream width. Through comparison with the numerical solution accurately simulated with a MODFLOW groundwater flow model, the analytical solution derived by regarding the stream width as a point was evaluated. It was found that the error in the stream depletion calculated by the analytical solution can be reduced to less than 0.05 when the stream-well distance is greater than the stream width or when the stream depletion factor (SDF) is more than about 3,000 days. In addition, when the streambed hydraulic conductivity is less than 1 m/d, the hydraulic diffusion coefficient of the lower aquifer layer is less than 100 ㎡/d, the hydraulic diffusion coefficient ratio of the upper and lower aquifer layers is 5 or more, and the leakage coefficient between the layers is less than 0.0004 m/d, the overall analytical solutions were overestimated compared with the numerical solutions.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.524-529
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• 2002

In this paper, we report the development of two DEM (digital elevation model) generation algorithms over urban areas from an IKONOS stereo pair. One ("EpiMatch") is originally developed for SPOT images and modified for IKONOS images. It uses epipolar geometry for accurate DEM generation. The other is based on graph-cut algorithm in 3D voxel space. This algorithm is believed to work better on height discontinuities than EpiMatch. An IKONOS image pair over Taejon city area was used for tests. Using ground control points obtained from differential GPS, camera model was set up and stereo matching applied. As a result, two DEMs over urban areas were produced. Within a DEM from EpiMatch small houses appear as small "cloudy" patches and large apartment and industrial buildings are visually identifiable. Within the DEM from graph-cut we could achieve better height information on building boundaries. The results show that both algorithms can generate DEMs from IKONOS images although more research is required on handling height discontinuities (for "EpiMatch") and on faster computation (for "Graph-cut").